Detachable terminal board for electrical devices



July 26, 1938. E. B. FAIRBANKS DETACHABLE TERMINAL BOARD FOR ELECTRICAL' DEVICES Filed June 8, 19.35

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JIlfV/l/ m 67 Am 2 6 B l7rYEgoi-a. I Q I Y M 46 m 110 ATTORNEY Patented Jul 26, 1938 2,125,256

UNITED STATES PATENTOFFICE DETACHABLE TERMINAL BOARD FOR, ELEC TRICAL DEVICES Edwin B. Fairbanks, Goldwater, N. Y., assignor to (genxeral Railway Signal Company, Rochester Application June s, 1935, Serial No. 25,616

10 Claims. (01. 173-328) This invention relates in general to electrical only which is to be employed on a relay of the apparatus, and more particularly to a detachable type shown in Patent No. 1,766,665, granted to terminal board for electrical devices such as em- J. F. Merkel on June 24, 1930, but it is to be unployed in railway signalling systems or the like. derstood that a detachable terminal board em- Inrailway signalling systems, certain electrical bodying the features of the present invention devices such as relays form a part of a rather may be constructed to cooperate with many other complicated circuit arrangement, which makes it forms of electrical devices. In the relay illusvery important that the external electrical contrated in Fig. 2 by the dot and dash lines, it is nections to these relays are always placed on the merely necessary for an understanding of the proper terminal posts and are so secured to these .present invention to know that an upright cylin- 10 posts that a reliable low resistance electrical condrical relay housing 4 is provided with a cylindrinection is formed. However, it is necessary to cal horizontal insulated top 5 upon which a pluoccasionally remove the relays from the system rality of upright terminal bolts 6 are assembled.

,for replacement, repair or the like, and conse- The terminal bolts 6. are clamped to the relay is quently the large number of circuits involved in top 5 by nuts I, and these terminal bolts 6 are making such a change often results in delaying of course connected within the relay housing to -1orma1 operation of the signalling system for an various contacts, operating coils and the like in undue length of time, and also there is a great accordance with the usual practice. possibility of improperly replacing the electrical The detachable terminal board of the present connections with possible danger of improper invention as shown in Fig. 1 and Fig. 2 is formed 20 operation or of further delay. by two discs l0 and I2 of suitable insulating In viewof the above andother considerations, it material which are assembled one above the other is proposed in accordance with the present inbytwo studs H as shown in Fig. 1, or as may be vention to provide a terminal board upon which v seen in Fig. 2, these studs 14 extend upwardly external electrical conductors are permanently through a slot in the lower disc [2 with reduced secure and which can be installed on an electrical ends threaded into metal inserts l5 either molded device or removed therefrom with a minimum or otherwise held in the top disc H1. The top of manual operation and yet which is arranged to disc I0 thus assembled above the lower disc is provide a reliable low resistance connection bepermitted to slide horizontally through a limited tween the electrical conductors and the associated distance relative to the lower disc l2 as allowed by 30 parts of the electrical device. It is further prothe slots in the lower disc l2 which receive the posed to provide such a terminal board which can body portions of the assembling studs M. be arranged on the electrical device tocomplete A horizontal stud I8 is provided in the upper the electrical circuits involved only when the exdisc ill with a protruding hexagonal head and a 5 ternal electrical conductors are connected to the reduced diameter inner end threaded into a metal proper parts of the electrical device. insert l9 molded or otherwise secured in the Other objects, purposes and characteristic top disc Ill. The larger diameter portion of the features of the present invention will appear as stud I815 provided ith an 911111113; grgove the description thereof progresses, during which ceiving a forked upwardly extending end of a references will be made to the mp ny ng metal block 20 clamped within a hollow center 40 drawing, in which e portion of the lower disc i2 by a screw M. This Fig. 1 is a planview of one form of a detacharrangement obviously permits the upper disc able terminal board constructed in accordance lllto be moved to the right from its position shown with the present invention. in Fig.2 relative to the lower disc lTby turning 5 Fig. 2 is an elevational sectional view of the the stud l8 inacounter-clockwise direction which terminal board shown in Fig. 1 taken substanforces the threaded insert l9 and the top disc tially on line 2 2 and viewed in the direction ID to the right relative to the stud l8 which is indicated by the arrows, the terminal board beheld stationary by the block "20 attached to the ing herein illustrated as applied to one form of a lower disc 12, the motion of the top disc l0 up relay indicated by dot and dash lines. the lower disc l2 being guided-by the slots in 50 Fig. 3 is a, sectional view illustrating a modifithe lower disc l2 which recsire the assembling cation which may be made in the terminal board studs l4. shown in Fig. 1 and Fig. 2. The discs I! and I2 assembled in this manner In the accompanying drawing, a detachable are normally supported abovethe top 5 of the terminal board has been illustrated in one form relay, and holes are provided in the lower disc 55 of each of the relay terminal bolts 6. The top disc I carries terminal bolts 22 arranged above these holes in the lower disc 'l2 and corresponding to each of the terminal bolts of the relay.

The square heads of the terminal bolts 22 rest in rectangular depressions inthe top disc ill with one side of these heads engaging a side of the depression to prevent turning. Spring contacts 24 01' a substantial S-shape have their upper ends clamped between the heads of the terminal bolts 22 and the top discs [0, the terminal bolts 22 and contacts 24 being clamped on the top disc ill by nuts 25. f

The S-shaped spring contacts 24 extends downwardly into the hollow center portion of the lower disc I2 with their lower ends engaging the sides of associated relay terminal posts 6 as shown. A contacting surface may be formed in the lowerends of the spring contacts 24 by a pressed-out portion as shown; and when the detachable terminal board thus formed is arranged on the relay as "shown in Fig. 2, the spring contacts 24 will be biased with considerable force against the sides of their associated relay terminal postsii, this biasing .force being provided. by the left-hand position of the disc l0 relative to the disc i2.

In other words, before installing the terminal board assembly upon the relay, the top disc Iii is operated to theright relative to the lower disc I2 by a counter-clockwise turning of the studl8, thereby operating-the spring contacts 24 to the right relative to the holes in the lower disc l2 which receive the relay terminal bolts 6, and in this manner the terminal board assembly may be easily applied as the spring contacts 24 will not engage the top portion of the relay terminal bolts 6. When the terminal board assembly is in,place,

. the stud l8 may be turned in a clockwise direction to provide and retain the desired contacting pressure between the spring contacts 24 and the relay.

-- terminal posts 6. In the present arrangement, the

resiliency of the spring contacts 24 assures that a good electrical connection will be made with the associated relay terminal posts \6 regardless of slight differences between the spacing of the relay terminal posts 6 and the posts 22.

. Flexible electrical conductors for connecting the relay to the external circuits are to be permanently connected to the terminal posts 22 on the 7 top disc I}, andoneor more clamping nuts 28 may be providedtor this purpose so that low resistance' electrical connections are made from these conductors on the terminal posts 22 to the relay terminal posts 8 through the contact springs 24. 'When it is necessary toremove the relay from the system, the horizontal stud I8 is turned in a counter clockwise direction thereby moving'the top disc II to the right relativetothe lower disc l2 which relieves the biasing force of the spring contacts 24 against the relay terminal posts 6 and permits the terminalboard assembly to be easily removed from the relay. t

, In the form of the relay to which the present detachable terminal board is applied, .the terminal posts form a symmetrical arrangement, and

' consequently it is obvious that the terminal posts 22 would aline with terminal posts 0 of the relay in either of two positions-or that is, the detachable' terminal board assembly might be rotated 180 degrees irom its proper pomtionwith respect to the relay, and in such a positionthe terminal posts 22 would still aline'with certain terminal posts 8 of the relay. the present terminal board assembly could be thus improperly applied board assembly is prevented by the provision of two spacing bushings 30 (see Fig. 1) which are threaded over two extreme right-hand terminal posts 6 thus being a permanent part of the relay; and two bosses 32 are provided on the bottom disc i2 around the holes receiving the two extreme left-hand relay posts 6', which bosses 32 may be integral or otherwise permanently attached to the detachable terminal board assembly. These spacing bushings and bosses 32 incidently serve to space the terminal board assembly a proper distance about the relay top 5, but also prevent the completion of electrical circuits if the terminal board is improperly replaced on the relay inasmuch as the bosses 32 would then engage the top.

spaced locations as the terminal bolts 22 in Fig. 1- and Fig. 2. Contact springs 24 similar to the contact springs 24 of Fig. 2 are placed on the lower ends of the bushings 34 against the lower flanges and the extending lower ends 01 the bushings 34 are flared or spun over the contact springs 24 thereby rigidly attaching the contact springs 24 to the bushings 34. Stud bolts 22 are threaded into the bushings 34 for clamping external electrical conductors against.

the upper flanged end of bushings 34, and it may be desirable to provide stud bolts 22 which have heads insulated from their body portions whereby to prevent short circuits from occurring inlthe event metal objects are accidently placed upon the relay terminal bolt assembly.

' A terminal board for electrical devices has thus been provided having means for permanently securing flexible electrical conductors thereto and .whlch may be easily and quickly installed on an electrical device and by a single manual'operation the terminal board may be manipulated to provide a reliable low resistance connection between the electrical conductors and the associated parts of the device. Likewise. single manual operation manipulates the present terminallboard in a manner to permit it to be easily and quickly removed from the electrical device, .and the present terminal board is arranged to prevent replacement upon the electrical device in amanner to improperly complete. electrical circuits. In other words, a detachable terminal board has been provided for electrical devices which permits a device to be'removed from an electrical system and a replacement 135 made in a minimum length ot time and which member, screw means threaded into the metal without departing from the spirit of the invention defined in the following claims.

- What I claim is:

1. A terminal board for electrical devices having extending terminal posts, comprising a lower insulating member receiving the terminal posts of the electrical device, an upper insulating member movably assehbled on the lower insulating member, wire terminal means on the upper insulating member, contact springs attached to the wire terminal means and extending downwardly to engage sides of the terminal posts of the electrical device, and a threaded manually operable means for moving the upper insulating member transversely to the posts and relative to the lower insulating member, whereby to engage or disengage the contact springs and the terminal posts oi the electrical device.

2. A terminal board for electrical devices having extending terminal posts, comprising a lower insulating member receivingthe terminal posts or the electrical device, an upper insulating member movably assembled on the lower insulating member, wire terminal means on the upper insulating member, resilient contact springs attached to the wire terminal means and extending downwardly to engage sides of the terminal posts of the electrical devices, and means for moving the upper insulating member transversely to the posts and relative to the lower insulating member.

8., In a terminal board for electrical devices having extending terminal posts, a first insulat ing member receiving the terminal posts, a second insulating member having wire terminal means, resilient contact members carried by the wire terminal means of the, second insulating member, and means for moving the second insulating member transversely to the posts and relative to the first insulating member in a manner to engage the contact members with the terminal posts.

4. In a detachable terminal board for electrical devices having extending terminal posts, a first insulating member having holes receiving the terminal posts, a second insulating member having wire terminal means, resilient contact members carried by the wire'terminal means of the Y second insulating member, and means for moving the second insulating member transversely to the posts and relative to the first insulatin member whereby to engage the contact .mem-

bers'with the terminal posts.

5. In a detachable terminal board for electrical devices having extending terminal posts, a first insulating member having holes fitting over the extending terminal posts, a second insulating member slidably mounted on the mat insulating member, metal bushings in the second insulating bushings ior attaching electrical conductors, re-

silient spring contacts attached to the metal bushings and extending into the first insulating member, and means rotatably carried by the first insulated member and threaded into the second insulating member for engaging the spring contacts with the terminal posts.

6. In an electrical system, a device having parallel extending terminal posts, a first member fitting longitudinally over the terminal posts, a second insulating member having permanent wire connections, and contacts attached to the wire connections and engagable with the terminal posts by a movement of the second member relative to the first member and transversels to the terminal posts.

'7. In an electrical system, a device having extending terminal posts, a first member fixed transversely with respect to the alinement of the terminal posts, a second member having wire terminal means engagable with the terminal posts by a movement of the second member relative to the first member transversely with respect to the alinement oi the terminal posts.

8. A detachable wire connecting means for terminal posts, comprising a first'member fitting over the terminal posts. a second member mounted to move on the first member in transverse relation to the terminal posts, and wire terminal means on the second member having resilient contacts biased against the terminal posts in accordance with the position of the second member 01' the first member.

)9. In an electrical system, a device having parallel extending terminal posts, a first member fitting longitudinally over the terminal posts, a boss on the first member fitting longitudinally over one of the terminal posts, a second insulating member having permanent wire connections, contacts attached to the wire connections and engagable with the terminal posts by a movement of the second member transversely to the extending terminal posts and relative to the first member, and a bushing carried by a terminal post 01' the device and cooperating with the boss on the first member to permit installation 0! the first member over the terminal posts only in one relative position.

10. A detachable wire connecting means for terminal posts, comprising a first member fitting over the terminal posts, a second member mounted to move on the first member in transverse relation to the terminal posts, wire terminal means on the second member having resilient contacts biased against the terminal posts in accordance with the position of the second member on the first member, and means on a terminal post engagable with means on the firstmember for preventing improper installation of the first member over the terminal posts; 

